5L 


Circular  n 


United  States  Department  of  Agricultur 


Al)    'H      I    N  lOMOl.i  »OY. 


I  III      IV    till 


DEPOSITORY 


:    vrn  i    1 1:1  i    UOR1  RS. 


;   ii 

In  t'luv 

Lmong  the  most   troublesome  of  the  insecl   pests  with 
fruit  imi>\\ ers  of  the  United  States  have  to  deal  are  two  9pecios  ■  >Tl »•  >r 
uil:  beetles  known,fTom  1 1  h •  appearance  o\  their  larvie,  as  the  round 
headed  and  flat-headed  apple-tree  borers.     The  firsl  of  these  belongs 
to  the  family  Cerambycida  and  the  other  to  the  Buprestida?.     In  ad 
tlit  ion,  there  is  a  not  her  species  called,  after  the  adult  form,  the  -|>nt  ted 
apple-tree  borer  and  to  distinguish  it  from  the  round-headed  borer, 
which   it    closel)    resembles.     The   two   species   firs!    mentioned   are 
common  and  injurious  throughout    a   wide  extenl   of  country     the 
former  to  Beed  fruil  trees,  the  latter  also  to  stone  fruil  as  well  as  to  a 
great   variet)   of  foresl   and  ornamental  trees.     The  third  is  a  com- 
parative!}   rare  insecl   and   rather  exceptional!}    injurious  so  fai    as 


kn 


nun. 


THE   ROUND-HEADED   APPLE-TREE  BORER. 

!.>!„  Fab. 


INTBODUCTOR1     BJEMABKS     k.N"D   DESCRIPTION 

The  round-headed  apple-tree  borer  i-.  nexl  after  tin-  codling  moth, 
the  worst  enemy  to  apple  culture  in  America. 

Tin"  firsl  intimation  that  the  grower  may  have  of  the  present 
this  borer  in   his   trees,   unless  he  be  forewarned.   i<  in   their  retarded 
2  -07 


growth  and  the  sawdust-like  castings,  consisting  of  excrement itious 
matter  and  gnawings  of  woody  fiber,  which  the  larvae  extrude  from 
the  openings  into  their  burrows.  This  manifestation  is  usually 
accompanied  by  more  or  less  evident  discoloration  of  the  hark  and, 
in  early  spring  particularly,  by  slight  exudation  of  Bap. 

The  parent  of  this  borer  is  a  beautiful  heetle,  measuring  from  three- 
fourths  to  nearly  an  inch  in  length,  the  male  being  perceptibly  nar- 
rower than  the  female.  The  antennae  are  long,  stout,  and  many- 
jointed,  being  somewhat  shorter  than  the  body  of  the  insect  itself. 
These  organs  and  the  legs  arc  gray,  the  undersurface  of  the  body  and 
the  head  arc  silvery  white,  and  the  upper  surface  is  light  yellowish 
brown  with  two  longitudinal  white  stripes  extending  through  the 
thorax  and  elytra  or  wing-covers  to  the  tip,  as  is  shown  in  the  accom- 
panying figure  1 .  c. 

The  larva,  when  mature,  measures  from  three-fourths  to  a  little 
over  an  inch  in  length  <22-26mm).  It  is  legless,  fleshy,  and  some- 
what grub-like  in  appearance,  cylindrical  in  form,  and  light  yellow 
in  color.  The  head  is  darker,  particularly  about  the  mandibles, 
which  arc  nearly  black.  The  first  thoracic  segment  is  large  and  broad 
and  bears  on  its  summit  numerous  small  tubercles,  placed  closely  to- 
gether. The  remaining  joints  of  the  body  are  narrower,  the  constric- 
tions between  them  being  deep  and  conspicuous.  The  first  seven 
abdominal  segments  bear  on  the  upper  surface  of  each  a  peculiar 
elevated  process,  as  shown  at  figure  1,  h. 

The  pupa,  illustrated  at  '/.  i-  nearly  as  long  as  the  adult  insect, 
which  it  resembles  in  a  superficial  manner,  the  head  being  bent  down 
toward  the  breast,  and  the  legs  and  long  antenna'  folded  upon  the 
ventral  surface.     Its  color  is  similar  to  that  of  the  larva. 

Saperda  Candida  was  given  its  specific  name  by  Fabricius  in  the  year 
1787,  and  was  again  described  as  new  by  Thomas  Say,  in  1824,  under 
the  name  of  S.  bivittata,  the  latter  remarking  at  the  time  that  it 
injured  apple  trees  by  boring  into  the  wood. 

DISTRIBUTION. 

This  species  is  native  to  this  country  and  is  present  in  injurious 
numbers  in  practically  every  State  of  the  apple-growing  region  east  of 
the  Rocky  Mountains.  It  inhabits,  like  so  many  other  injurious  in- 
sects, the  upper  austral  and  transition  life  zones,  comprising  the  better 
agricultural  portion  of  all  except  the  extreme  southern  States.  It  has 
been  reported  to  occur  in  one  locality,  Agricultural  College,  Miss., 
which  lies  in  what  is  considered  the  lower  austral  zone.  As  with 
many  other  noxious  species,  too,  it  is  in  the  older  States,  particularly 
of  New  England  and  New  York,  where  orchards  have  been  long  estab- 
lished, that  injuries  are  most  pronounced.     Until  recently  this  species 

[Cir.  32] 


B 

was  not  known  as  especially  injurious  aboul  the  District  of  Columbia, 
l>ui  at  the  present  time  it  has  become  verj  abundant  and  destructive, 
whole  orchards  both  of  young  and  mature  trees  having  succumbed  to 
n  -  r:i\  ages. 

It-  known  distribution  includes  <  anada,  all  of  the  Ke^  England 
States,  \ew  York,  \ew  Jersey,  Pennsylvania,  Delaware,  Maryland, 
Virginia,  West  \  irginia,  District  of  Columbia,  Ohio,  Illinois,  Michigan, 
Iowa.  Missouri,  Kansas,  and  restricted  localities  in  Texas,  AJabama, 
and  Mississippi. 

FOOD    PLANTS     IND    NATURE  Ol     INFESTATION. 

This  Koicr  i-  practical!}  limited  in  its  food  to  the  apple  and  kindred 
wood}  plants.  It  is  most  injurious  to  quince  and  apple,  and  Bome- 
w  hat  less  so  to  pear.  It  infests  also  crab  apple  and  thorns  of  different 
specie-,  mountain  ash,  chokeberry,  and  juneberrj  in  short,  practi- 
cally all  except  one  or  two  kinds  of  trees  and  shrubs  belonging  to 
genera  included  in  the  family  Pomaces?.  The  wild  plants  are  its  natu- 
ral Too. I.  but  certain  varieties,  at  least,  although  often  inhabited  by 
tlii-  insect,  arc-  for  ason  not  so  susceptible  to  ii>  injur}  as  are 

our  cultivated  i  rees.  Tin-  species  inhabits  more  particularly  the  base 
of  the  trunk  of  trees,  often  being  found  lie  low  the  surface  i  f  the  earth, 
especially  in  young  nurser}  stock.  It  is  to  such  trees  that  it  is  most 
injurious,  for  it  s(.on  works  around  the  trunk,  separating  the  wood 
from  the  hark,  interfering  with  the  flo'w  of  sap,  and  producing  the 
effect  of  girdling,  a  result  which  is  very  apt  to  be  produced  even  when 
no  more  than  two  or  three  larva'  occur  on  tin-  same  tree.  \  ei  \  fre- 
quently four  or  live  larva'  dwell  together  in  a  single  small  tree  and  in 
a  short  time  injure  it  quite  beyond  recovery  .  In  old  trees  larva  occur 
.somewhat  higher  up  the  trunk,  in  exceptional  <  a-e-  at  a  distance  of 
se\  era  I  fee!  from  t  lie  ha -e  or  even .  -1  ill  more  rarely,  in  the  lower  linihs. 

As  a  rule,  however,  t  key  are  seldom  found  except  within  a  fool  or  two 
of  the  base.  Tree-  of  all  sizes  are  frequently  killed  or  weakened  bo 
such  an  extent   that   they  are  unable  to  mature  a  full  crop  of  fruit. 

The  experience  of  many  years  shows  that  injury  follow-  where 
grasses,  weed-,  or  other  rank  vegetable  growth  are  permitted  to  accu- 
mulate aboul  the  trunks  of  the  trees,  since  the  beetle,  like  all  nocturnal 
insects,  naturally  seek-  concealment,  and  the  condition-  thus  afforded 
are  most  favorable  for  its  attack  on  cultivated  plants. 

I. IKK    BISTORT. 

The  beetles  make  their  first  appearance  <<\  the  season  hue  in  May  or 
in  June,  according  to  locality  .     During  the  night  they  come  forth  from 

the  trunk-  of  the  trees  in  which  they  have  hied,  and  al  this  time  may 
he  seen  in  flight.      During  the  day  the\    bide  away  in  some  secluded 

[Cir 


place,  under  leaves  or  in  similar  situations,  on  the  trees  which  they 
inhabil . 

Soon  after  their  first  appearance  the  sexes  mate  and  eggs  are  de- 
posited. The  female  first  makes  an  incisionin  the  hark  probablyby 
means  of  her  mandibles  causing  it  to  split  slightly;  then,  turning 
head  upward,  she  places  an  egg  under  the  bark  nearly  a  quarter  of  an 
inch  from  the  incision,  accompanying  the  deposition  by  the  extrusion 
of  "a  gummy  fluid  which  covers  and  secures  it  to  its  place  and  usually 
fills  up  the  aperture.  In  young  trees  with  tender  hark  the  e«:g  is 
usually  thoroughly  hidden,  while  in  older  trees  it  is  sometimes  so 
shallowly  imbedded  as  to  he  readily  seen.'' 

'The  egg  is  pale  rust-brown  in  color,  one-eighth  of  an  inch  long, 
one-third  as  wide  at  the  middle,  flattened  so  as  to  have  a  depth  of 
about  one-third  the  width.""  Its  shell  is  fairly  tough  and  resistant, 
not  sculptured,  and  sufficiently  plastic,  when  laid,  to  receive  impres- 
sions from  the  woody  fibers  between  which  it  is  forced.  Oviposition 
has  been  observed  from  June  to  September  in  a  single  locality  (Law- 
rence, Kansas),  but  June  is  the  month  in  which  most  of  the  eggs  are 
laid.  Fitch  and  others  observed  the  beetles  in  the  trees,  near  Albany, 
X.  Y..  as  early  as  April. 

Regarding  the  duration  of  the  egg  stage,  Mr.  E.  W.  Junkins  b  states 
that  a  young  borer  larva  was  observed  July  7  from  e«;gs  that  were 
deposited  June  15.  This  would  give  a  period  of  twenty-two  days,  but 
Ave  have  no  further  data  bearing  on  this  point. 

The  larva?,  soon  after  hatching,  tunnel  under  the  hark  and  feed  on 
the  sap-wood,  gradually  working  their  way  upward  and  afterwards 
downward,  usually  remaining  within  a  short  distance  of.  or  below  the 
surface  of,  the  ground,  particularly  in  young  trees.  By  the  heginning 
of  the  second  year  the  larva',  according  to  observations  conducted  by 
the  writer,  attain  an  average  length  of  about  five-eighths  of  an  inch. 
The  larval  growth  will  naturally  vary  according  to  temperature,  mois- 
ture, quantity  of  food  available  for  consumption,  and  other  condi- 
tions. With  the  approach  of  cold  weather  the  larva'  cease  feeding, 
but  with  the  beginning  of  warm  spring  weather— in  the  District  of 
Columbia  as  early  as  the  latter  days  of  March  they  again  commence 
forcing  their  excrement  and  castings,  consisting  of  gnawed  particles 
of  wood,  out  through  holes  which  they  make  in  their  burrows.  By 
the  end  of  the  second  year  the  larva-  have  increased  considerably  in 
size  and  have  now  penetrated  deeper  into  the  solid  heart-wood,  their 
burrows  being  closely  packed  behind  them  with  castings.  The  third 
year  the  larva?  gnaw-  outward  to  the  bark,  form  a  pupal  cell  composed 

a  Above  quotations  from  account  by  Riley  in  New  York  Weekly  Tribune,  Feb.  20, 
1878;  Kans.  Hort.  Rept.  for  L879,  pp.  L96-201. 
frNew  England  Bomestead,  .Ian.  3,  1885. 
[Cir.  32] 


partly  of  1 1  leu'  i  astings  and,  with  their  headc  pointin  •  toward  the  bark, 
transform  to  pupae.  With  the  approach  of  Ma)  and  June  thej  cul 
their  waj  out  l>\  means  of  their  powerful  mandibles  and  issue  through 
■  round  hole  as  mature  beetles.  V  larva  was  observed  b)  the  writer 
ai  the  Department  ol  \  riculture  thai  pupated  Maj  1 1 ,  and  appeared 
as  adult  Ma\  30,  thus  nineteen  days  for  the  pupal  period,  the 

uc;ii her  being  seasonable. 

\  \  i  i  i:  \  i     ENEMIES 

Concealed  as  this  insect  is  during  its  three  years  of  existence  in  its 
preparatory  stages,it  is  nevertheless  a  prej  to  natural  enemies  which 
seek  and  devour  it  in  its  haunts  under  the  bark.  Of  this  number  are 
woodpeckers  and  hymenopterous  insect  parasites.  <  M'  the  latter  only 
•  single  species  is  known  to  the  writer.  Cenocaliw  populato    - 

\i  1. 1  B<  IDS  Ol     <  ON  l  ttOL. 

After  borers  have  once  entered  a  tree  there  is  no  better  remedy 
known  than  to  cut  them  oul  with  a  knife  or  other  sharp  instrument. 
In  the  t reat men t  of  this  insect  an  ounce  of  prevention  is  worth  several 
pounds  of  cure.  Cutting  the  borers  out,  unless  practiced  with  the 
greatest  care,  is  apt  to  resull  in  injury .  and  it  is  far  better  to  prevent 
the  parent  insects  from  depositing  their  eggs  upon  the  tree.  This  is 
not  difficull  of  accomplishment,  as  oviposition  is  practically  confined 
t<>  two  months  in  an\  -mule  localit}  .  usuallj  dune  ami  duly.  The  best 
preventives  are  impenetrable  substances  placed  about  the  trunk  and 
variou>  washes  of  a  repellent  nature. 

Cutting  out  by  hand.  Little  has  Keen  gained  in  the  line  of  direct 
remedies  for  this  borer  until  recent  years.  The  early  writers  had  noth- 
ing better  to  advise  than  cutting  oul  the  larvae,  either  with  a  knife  or 
gouge,  or  killing  them  l>y  inserting  a  wire  into  their  burrows.     Thi  ae 

remedies  were  in  Use  early  in  the  presenl  cent  ur\   and  are  still  I  he  ones 

most  often  practiced.  It  is  do  uncommon  thing  to  find  four  or  more 
larva'  in  a  single  small  trunk,  and  t  he  cutting  oul  of  all  of  them,  if  not 
practiced  with  the  greatest  caution,  is  apt  to  result  m  the  girdling  of 
the  tree.  if.  indeed,  this  has  not  already  Keen  accomplished  1>\  the  com- 
bined attack  of  the  borers  themselves.  It  would  seem  superfluous  to 
add  that  it  is  hot  to  cut  the  borers  out  as  soon  as  detected.  Their 
presence  may  he  known  h\  a  little  experience, some  persons  being  so 
('Xpert  m  detecting  t  heir  exact  local  ion  as  to  be  a  hie  to  kill  t  hem  with 
a  knife  thrust  or  hv  the  puncture  of  an  awl  or  other  sharp  instrument. 
The  fruit  grower  should  institute  a  practice  of  inspection  so  that  the 

borers  may  he  removed  as  often  as  found. 


■>  Mentioned  in  [nseel  Life,  Vol.  Ill  nachus  say  da  In! 


6 

To  assist  a  tree  in  recuperating  after  it  has  been  girdled,  a  bridge  or 
two  should  be  made  by  splitting  a  piece  of  apple  twig  (say  of  an  inch 
or  two  in  thickness),  cutting  it  diagonally  on  the  inside,  and  applying 
to  the  surface  at  the  base  of  the  tree.  It  should  then  be  tied  on  and 
grafting  wax  applied  to  each  end,  after  which  a  fertilizer  should  be 
applied  and  the  whole  hanked  over  with  earth.  It  is  also  well  to  keep 
the  tree  watered  for  a  few  weeks  after  treatment. 

Mechanical  jm  rentives. — This  is  one  of  the  borers  that  can  readily 
be  controlled  by  different  sorts  of  mechanical  barriers  placed  about  the 
base  of  the  tree.  For  this  a  few  thicknesses  of  newspaper  wrapped 
rather  loosely  about  the  trunk  and  extending  about  two  feet  from  the 
base  are  all  that  is  necessary.  Tins  covering  should  be  tied,  by  pref- 
erence with  cord,  which  will  readily  yield  or  break  with  the  natural 
expansion  of  the  tree  in  its  growth,  and  also  be  tightly  fastened  at  top 
ami  bottom  and  hilled  up  with  earth  so  thai  the  beetles  can  not  obtain 
access  to  the  tree  from  below.  From  the  top  of  this  covering  upward 
it  is  best  to  use  some  deterrent  alkaline  or  carbolated  wash.  Instead 
of  newspapers,  wire  gauze  or  mosquito  netting  may  be  used,  and 
should  be  put  in  place  so  as  to  loosely  encircle  the  tree,  that  the  beetles 
may  be  debarred  from  depositing  their  eggs  between  its  meshes  and 
that  the  growth  of  the  tree  may  not  be  hindered.  Both  devices  have 
been  successfully  employed  for  a  long  period  of  years,  and  there  is 
abundant  testimony  to  their  value.  If  the  netting  or  paper  be  put  in 
place  early  in  May,  it  will  not  only  prevent  the  beetles  from  oviposit- 
ing during  the  next  two  months,  but  will  also  keep  the  insects  which 
might  be  present  in  the  trunk  from  issuing,  and  they  will  die  in  their 
burrows  without  being  able  to  lay  fertilized  eggs.  The  paper  wrap- 
ping must  be  removed  each  season,  but  the  wire  netting  will  last  for 
several  };ears.  It  is  safe  to  remove  either,  ordinarily,  after  the  first  of 
September. 

Protective  trashes. — Any  one  of  several  washes  in  general  use  against 
boring  insects  may  be  used  as  a  deterrent.  A  good  alkaline  wash  is 
prepared  of  soft  soap  reduced  to  the  consistency  of  thick  paint  by  the 
addition  of  caustic  potash  or  washing  soda  in  solution.  A  good  fish- 
oil,  or  whale-oil,  soap,  or  common  soft  soap,  is  often  used,  and  in  some 
cases  any  one  of  these  is  sufficient  to  deter  the  insects  from  depositing 
their  eggs.  The  alkaline  wash  may  be  carbolated,  if  desired,  by  the 
addition  of  crude  carbolic  acid,  at  the  rate  of  1  pint  to  every  10  gal- 
lons of  the  wash.  Such  a  wash  not  only  affords  protection  against 
this  and  other  borers,  but  against  scale  and  fungous  diseases  at  these 
points,  and  is,  moreover,  of  positive  benefit  to  the  tree.  Caustic  pot- 
ash fish-oil  soaps  are  among  the  best  for  insecticides. 

Whatever  wash  is  used  should  be  applied  thoroughly,  and  in  locali- 
ties where  apple-tree  borers  are  unusually  troublesome  the  larger 

[Cir.  32] 


branches  should  also  be  covered  as  far  a--  possible.     The  wash  ma}  be 
best  applied  with  a  whitewash  brush  and  should  be  renewed  al  int< 
vnU  of  from  i  w "  i"  four  weeks,  as  found  necessary,  the  firsl  applies 
tioii  being  made  before  the  appearance  of  the  insects  in  Ma}  or  June 
anil  again  during  Jul}  . 

Ii  is  well  t"  scrape  old  trees  i"  remove  dead  bark  Bcales,  care  being 
taken  n< >i  to  cause  an}  abrasion.  Scraping  is  besl  done  some  time 
before  the  application  of  tli«'  wash  so  thai  the  wounds  tliai  mighl  be 
made  maj  have  opportunity  to  heal  before  the  appearance  of  the 
beetles. 

The  I ties  are  shy,  and  so  seldom  seen  that  il  is  doubtful  if  any 

method  of  destroying  them  ia  feasible,     The}  are  atl  racted  to  lights  al 
night  to  some  extent,  and  some  meel  their  end  in  this  way. 

Keroseiu  as  n  remedy.  A  great  variety  of  substances  has  been 
recommended  i<>  kill  the  borers  in  the  trees,  but  up  t"  the  present  time 
only  a  few  have  given  satisfaction.  For  the  benefil  of  those  who 
have  not  hail  experience  with  this  borer  it  ma}  he  necessar}  t"  state 
that  it  is  of  no  avail  whatever  to  inject  kerosene  or  an}  other  insecti- 
cide into  the  round  holes  made  by  the  beetles  in  then-  escape  from 
the  trees.  A  correspondent  of  this  Bureau,  Mr.  'I'.  Ii.  Ashton,  who 
has  had  man}  years'  experience  with  this  borer,  states  that  there  is 
no  better  wa}  <<(  effectually  putting  a  stop  to  the  depredations  of  this 
and  similar  borers  than  in  the  use  of  kerosene  applied  freely  wherever 
the  castings  <>(  the  larvae  are  to  he  seen  protruding  through  the  hark. 
The  kerosene  is  absorbed  b}  the  castings  and.  carried  by  capillary 
attraction,  permeates  the  entire  burrow.  It  thus  come-  in  contact 
with  the  larva,  which  soon  succumbs.  The  amount  of  kerosene 
necessary  i-  so  small  that  it  doe-  not  endanger  the  health  of  the  tree. 

Clean  cultural  methods.  Finally,  clean  culture,  the  best  preventive 
for  insect  injury  of  whatever  kind,  should  not  be  neglected.  The 
nursery  should  nol  be  started  in  new  localities  where  crabapples, 
thorn.-,  juneberry,  and  other  wild  food  plant-  of  this  species  gro\<  in 
greal  profusion,  nor  in  the  vicinity  of  neglected  orchards,  nor  should 
rank  growths  of  weed-,  grasses,  bushes,  and  briars  he  permitted  to 
accumulate  about  the  trunk-  of  the  tree-.  When  a  tree  i-  -ecu  to 
be  injured  beyond  recover}  it  should  be  taken  out  and  destroyed  by 
burning  before  the  following  spring,  so  that  the  larva'  which  it  eon- 
tain-  ma}  not  have  an  opportunity  to  develop  and  infest  healthy 
growth. 

THE   SPOTTED   APPLE-TREE   BORER. 

A  related  insect  very  similar  to  the  preceding,  both  in  appearance 
and   in    habits,    i-    the   -potted     apple-tree    borer.      The   beetle   i-   of 
nearly  the  same  size  and  form,  differing  superficially  by  having  two 
[Or.  a.*) 


white  spots  on  each  elytron  (fig.  2)  instead  of  the  longitudinal  white 
lines  which  distinguish  the  latter  (fig.  1,  c).  The  larva  and  pupa  are 
so  similar  that  no  description  need  be  made  of  them.  Although 
the  species  has  a  fairly  wide  distribution,  corre- 
sponding somewhat  closely  to  that  of  the  com- 
mon species,  specific  injury  by  it  has  only  been 
noted  in  two  States,  namely,  in  Michigan  by 
Prof.  A.  J.  Cook  and  in  Iowa  by  Prof.  H.  Osborn. 
In  the  former  State  this  borer  is  reported  as 
quite  as  common  and  destructive  as  Saperda 
Candida.  Its  occurrence  is  recorded,  also,  in 
.  fc_  Canada,  Massachusetts,  New  York,  Pennsylvania, 
male  beetle  eniargedone-  Wisconsin,  and  Ohio,  and  there  are  specimens  in 
the  National  Museum  from  northern  Illinois  and 
Texas.  Apple  and  wild  crab  are  the  only  plants  which  it  has  been 
observed  to  injure,  but  its  occurrence  has  been  noted  on  juneberiv 
and  thorn.  According  to  Osborn  the  "eggs  are  evidently  laid  in 
pairs,  half  an  inch  or  more  apart,  along  the  branch,  the  larva1  of  each 
pair  upon  hatching  working  in  opposite  directions  around  the  branch, 
at  first  just  beneath  the  bark,  afterwards  (probably  after  the  first 
year)  entering  the  hard  wood." 

The  remedies  for  this  species  are  the  same  as  for  the  preceding 
with  the  extra  precaution  that  the  larger  branches,  also,  he  protected 
by  the  wash  applied. 

THE  FLAT-HEADED  APPLE-TREE  BORER. 

(  Chrysobothris  femorata  Fab.  I 

GENERAL    APPEARANCE    AND    NATURE    OK    INJURY. 

A  much  less  dangerous,  though  more  abundant,  insect  than  an}*  of 
the  preceding,  is  the  flat-headed  apple-tree  borer.  It  belongs  to  the 
short-horned  wood-borers  or  metal- 
lic beetles  of  the  family  Buprestida?, 
and  differs  remarkably  from  the  pre- 
ceding in  all  its  stages  as  well  as  in 
its  habits  and  life  history. 

The  adult  insect  (represented  at 
b,  fig.  3)  measures  from  a  little  less 
to  a  little  more  than  a  half  inch  in 
length.  It  is  flattened  above  and 
bears  some  resemblance  to  a  snap- 
ping beetle,  but,  unlike  the  Elateri- 
dse,  is  not  provided  with  jumping 
organs.  The  antenna1  are  short  and 
serrate,  the  eyes  large  and  conspicuous,  and  the  forelegs  are  armed  in 
front  with  a  conspicuous  tooth.     The  upper  surface  of  the  body  is 

[Cir.  32] 


Fig.  3.— Chrysobothris  femorata:  a,  larva;  6, 
beetle;  e,  bead  of  male;  </.  pupa— twipo  nat- 
ural size  (original). 


dark  metallic  brown,  and  fresh  specimens  are  coated  here  and  tl 
with  n  powdery  gra}  substance,  which  i-  easil}  rubbed  off.     The  wii 
covers  are  ornamented  as  shown  in  the  illi  n,  and  underneath, 

as  ma}  be  seen  when  the  insect  is  in  flight,  the  bod}  isabrighj  metallic 
greenish  blue.  The  under  surface  is  coppery  bronze.  The  males  are 
smaller  and  ma}  1"'  further  distinguished  from  the  females  b}  their 
green  beads,  as  \\ ell  a--  b}  ol her  ch 

Unlike  the  round  beaded   borer  the  present   specii  urnal  in 

habit,  being  mosl  active  in  the  heal  of  the  da}  and  commonlj  found 
mi  prostrate  trees  and  logs,  or  on  injured  trunks,  basking  in  the  sun- 
light. The  beetles  are  active  creatures,  running  rapidly  and  flying 
readily . 

This  borer  attacks  diseased  or  dyii  b}   preference,  inhabits 

all  parts  of  a  tree  from  the  base  of  the  trunk  to  the  limbs,  and  is  not 
restricted  to  fruil  trees,  bul  attacks  a  variety  of  deciduous  trees,  also. 

In  all  these  respects  it  differs  from  the  round-headed  borer,  bul 
agrees  with  the  latter  in  that  it  i-  injurious  chief!}  i"  young  trees,  its 
injuries  being  practically  confined  to  newl}  transplanted  aurserj  3tock 
and  to  trees  which  have  been  weakened  through  an}  cause,  such  as 
careless  pruning,  or  insufficient  nourishment  due  to  poor  soil  or 
drought.  There  is  a  difference  of  opinion  as  to  the  nature  of  dams 
some  writers  taking  the  stand  that  health}  trees  are  not  injured  at  all. 
It  is  a  well-known  fact  that  man}  forms  of  boring  insects  prefer  injured 
plants,  but  when  these  are  wanting  do  not  hesitate  to  attack  perfectly 
sound  growth,  and  records  show  conclusivel}  that  the  present  species 
i-  included  in  this  category.  The  general  opinion  is  that  tree-  suffer- 
ing from  "sun  scald"  are  mosl  subject  to  attack,  and  the  opinion  has 
been  expressed  that  injury  known  under  this  name  i-  in  reality  due  to 
the  work  of  this  borer.  The  beetle  i-  essentially  a  sun-loving  species 
and  deposits  it-  eggs  almost  exclusively  on  the  southern  or  south- 
western side  of  standing  trees  or  on  recently  felled  logs  thai  are  exposed 
to  direct  sunlight.  Observation  lead-  us  to  have  doubts  a-  to  the 
ability  of  the  young  larva'  to  withstand  the  strong  flow  bag  sap  of  \ 

OIOUS  tree-. 

Infestation  may  he  detected  by  the  discoloration  of  the  hark. 

A   li-t    of  the   recorded    food    plants  of   thi-   borer   include-,   among 
orchard   tree-,  apple,  pear,  and   peach:  and  of  -hade  and   fore-t    trees, 

mountain  ash,  oak,  maple,  box-elder,  hickory,  chestnut,  sycamo 
horse-chestnut,  linden,  and  willow.     To  this  list  should  be  added  plum 

Note.— A  third  -|"  similar  habits  and  is  tiki 

attack  apple  and  similar  cultivated  pomao  bul  is  thus  far  known  only  "ii 

thorn      \  lull  accounl  of  thi  published  by  the  late  I>r.  Euunilt 

Ent  .  Vol.  XX.  pp.  6   - 

[Or. 


10 

and  cultivated  redbud  (Cerds  chinensis),"  from  which  the  species  has 
been  reared  by  the  writer,  and  currant.'' 

Cherry,  Kerch,  and  white  birch  arc  probable  food  plants,  although 
the  beetle  has  not  been  reared  from  tbem,  and  elm,  tulip,  and  cotton- 
wood  have  been  mentioned  as  such,  but  on  what  authority  is  not  clear. 
Oak  is  without  doubt  the  favorite  natural  Lost  tree. 

The  larva  differs  greatly  from  that  of  the  round-headed  borer.  Its 
name,  flat-beaded  borer,  is  derived  from  the  peculiar  Hat  expansion  of 
tbe  second  thoracic  segment  which  is  close  to  the  bead.  Jn  color  it 
is  light  yellow  and  in  length  measures  nearly  twice  that  of  the  mature 
insect.  It  habitually  rests  in  a  curved  position,  more  bent  visually 
than  shown  in  the  illnst  ration  dig.  3,  a).  The  pupa  (d)  shows  the  form 
of  the  future  beetle  and  is  of  the  same  yellow  color  as  the  larva. 

This  species  inhabits  practically  the  entire  United  States  and  the 
southern  portion  of  Canada,  being,  like  the  preceding,  a  native  of 
North  America  and  injurious  year  after  year. 

NATTKAI.    HISTORY    AND    HABITS. 

The  beetles  make  their  appearance  about  the  same  time  as  the 
round-headed  borer  in  regions  infested  by  both  species-  after  the 
middle  of  May  in  the  principal  apple-growing  regions  of  the  Northern 
States — and  continue  through  the  month  of  July  and,  it  is  said,  even 
into  September,  the  female  depositing  her  eggs  in  cracks  and  grooves 
or  under  bark  scales  upon  the  trunks  or  branches  of  trees  destined  to 
be  the  future  food  of  the  larvae.  Most  frequently  several  eggs  are 
found  together.  These  are  yellow  in  color,  irregularly  ribbed,  and 
about  one-fiftieth  of  an  inch  in  length/  The  larva  differs  from  the 
round-headed  borer  in  that  only  a  single  year  is  required  for  its  devel- 
opment, pupation  occurring  in  the  spring  shortly  before  the  appear- 
ance of  the  beetles.  It  differs,  also,  in  its  manner  of  work,  living  for 
the  most  part  just  beneath  the  bark,  where  it  excavates  broad,  flat, 
and  very  irregular  channels.  Sometimes,  however,  it  enters  more 
deeply  into  the  sap-wood.  Like  many  other  borers,  it  will  often  girdle 
a  small  tree,  a  single  individual  being  capable  of  killing  a  small  tree  in 
this  manner.  As  it  approaches  maturity  it  generally  eats  deeper  into 
the  solid  heart-wood,  but  in  spring,  just  before  transformation,  it 
works  back  again  into  the  bark  and  there  constructs  its  pupal  chamber. 
It  is  said  to  remain  in  the  pupa  state  about  three  weeks,'  whereupon 
the  beetle  cuts  its  way  out,  leaving  in  the  bark  an  elliptical  exit  hole 
which  distinguishes  its  work  from  that  of  the  round-headed  borers, 
which  make  round  holes  in  their  exit.  These  holes  correspond  to  a 
cross-section  of  the  beetle  making  them.     In  the  North  the  winter 

o  Formerly  C.  japoniea. 

6  F.  H.  Hillnian.  Nevada  Expcr.  Station,  Bill.  36,  p.  18. 
c  C.  V.  Riley,  Proc.  Ent.  Soc.  Wash.,  Vol.  Ill,  p.  92. 
[Cir.  32] 


1 1 

months  are  passed  as  larvae,  bul   farther  south,  in  the  Districl   of 
Columbia,  according  t"  recent  observation,  pupation  ma}  take  pi 
as  earl]  as  November  of  the  firsl  yeai 

NATURA1     ENEMIES 

Among  natural  enemies,  woodpeckers  and  ants  are  effective  destroy- 
ers of  thi>  species,  since  thej  devour  larva?  and  pupa?  under  the  bark, 
A  number  "f  parasitic  insects,  also,  prej  upon  il  and  assist  greatrj  in 
rest  rid  ing  it  s  abundanci 

1:1  mi  mi  - 

The  remedies  advised  for  the  round-headed  borer  arc  also  of  value 
and  are  generally  employed  against  the  present  species  It  is  neces- 
sary .  however,  that  deterrent  coverings  and  washes  Bhould  be  applied 
farther  up  the  trunk  and  to  as  man]  branches  a-  can  be  conveniently 
reached.  As  this,  however,  necessitates  additional  labor  and  extra 
expense,  other  preventive  measures  are  also  recommended. 

'/'/•<//>  wood  for  tlu  beetles.  For  this  purpose  anj  sort  of  tree  known 
tc»  be  freel]  attacked  l>\  this  borer,  e.  </..  oak,  maple,  or  an\  fruit 
tree,  may  be  used.  If  a  few  1  i n » 1 »-  or  trunks  of  newlj  felled  trees  he 
placet  I  at  intervals  of ,  say,  30  or  10  feet,  on  the  outskirts  of  orchards, 
where  tlie\  are  freerj  exposed  to  the  sun,  the  beetles  will  be  attracted 
for  the  deposition  of  their  eggs,  and  all  that  will  then  be  necessary 
will  be  to  destroy  the  trap  wood  1>\  burning  before  April  or  Ma\  of 
the  following  year.  This  plan  has  nol  been  practically  tested,  hut 
the  writer  has  no  doubt  that  it  would  prove  useful  in  securing  im- 
munity from  this  pest  in  the  orchard,  provided  that  no  diseased  fruit 
trees  be  left  for  food. 

Careful  cultural  until, hIs.  Careful,  clean  methods  of  orchard  man- 
agement are  essential  a-  a  measure  of  protection,  and  involve  the 
cutting  out  of  dead,  dying,  and  injure. I  deciduous  forest  ami  shade 
as  well  a-  orchard  tree-  known  to  he  chosen  a-  food  l>\  tin-  species. 
Care  should  he  exercised  in  transplanting,  and  especially  in  pruning; 
and  fertilizers  should  be  used  in  order  that  the  trees  may  he  thrifty 
and  better  able  to  withstand  attack.  Proper  regard  for  these  m< 
ure-  should  u'ive  practical  exemption  from  injury. 

Approved : 
James  Wilson, 

s  i .  retary  <</  Agricultun  . 

Washington,  D.  C,  April8,  / 

Y    Riley,  Proc.  Ent.  - 
*>  The  li>t  includes  the  Brw  onids,  B  -  Riley  and  /• 

pallidtu  Ashm.,  and  the  Ichneumonids    /  ,  and      grallator  S       and 

en.'  ..r  more  ~i" ■■  Lee  •  I « ihalcidid  i  I  by  Fitch  ;i-  occurring  in  New  York  and  t>y 

Riley  in  Missouri. 

Nots. — First  issue,  July  1.  1898;  revise,  August  30,  I 

[Cir.  32] 

o 


UNIVERSITY  OF  FLORIDA 


3  1262  09216  4978 


